It is known to provide a film cassette with a light shield that can be closed to prevent ambient light from entering the cassette interior and can be opened to permit film movement out of and into the film cassette.
For example, commonly assigned U.S. Pat. No. 4,255,034, issued Mar. 10, 1981, discloses a film disk cartridge in which a core or hub for the disk film has a central opening for receiving a splined post (of a camera) in driving engagement to rotate successive sectors of the disk film beneath an exposure window in the housing of the cassette. A cover member is supported inside the housing for rotation about the core between a closed position over the exposure window and an open position removed from the exposure window. Engagement of a flexible tab on the cover member and a fixed tooth on an inside wall of the housing secures the cover member releasably in its closed position. An access hole is located in the housing to receive a release pin (of the camera) which disengages the tab from the tooth to permit the cover member to be rotated from its closed position to its open position. A separate pin (of the camera) engages the cover member to rotate the cover member to its open position.